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Saddle. A block of wood, hollowed out to receive the inner end of a jib-boom.

Safety Steps. Special non-slipping arrangements for the steps of ladders or stairs. When in the form of a surface attachment to existing steps, they are called safety treads. The most modern practice, however, incorporates the non-slipping feature in the step itself. One form of safety step consists of grating, set on edge and solidly riveted together so that it is ready to be attached to the frame of the ladder or stair.

Safety Treads. See Treads, Safety.

Safety Valve Box. The protective casing sometimes used to cover the safety valve and to prevent its being injured.

Safety Valves. See Valves, Safety.

Sag, Sagging. The drooping or tendency to droop of the midship portion of a vessel relative to the ends.

Sagged. Permanently deformed by the action of sagging forces.

Sail. An article made of canvas and rope designed to be spread on spars in such a manner as to utilize the power of the wind in driving a vessel. Sails are of two general classes: square and fore-and-aft. Square sails are suspended from yards. Fore-and-aft sails are spread on booms and gaffs or bent to stays.

Sail Needle. A strong needle with a large eye used by sailmakers.

Sail Plan. A plan drawn to show the number, arrangement and dimensions of the sails for a sailing vessel.

Sailing Vessel. See Vessel, Sailing.

Sailmakers. Workmen who work the canvas, rope and fittings up into sails, awnings, tarpaulins, weather cloths, covers, etc.

Sampson Post, King Post. A strong vertical post used to support a derrick boom.

Sand Glass. This device for measuring intervals of time has two pear-shaped glass bulbs, one above the other, joined together at their pointed ends or necks by a narrow tube, through which fine sand or marble powder slowly runs down in a pre-determined space of time.

Sand Jack. See Jack, Sand.

Sand Sucker. A scow, or hull of other form, on which is installed a large, power operated pumping outfit of the centrifugal type, arranged to take water from the bottom of the channel or river bed by means of a long pipe or tube and to discharge either through a pipe line, generally carried on floats, to any convenient point in the vicinity or into holds provided in the vesselís own hull.

Sander. A machine designed to automatically sandpaper and finish the surface of woodwork.

Sanitary Fixtures. Plumbing installations such as toilets, bath tubs, showers, lavatories, toilet cases,. waste jars, supply pitchers, carafe, water heaters, etc.

Sanitary System. A system of piping supplying and draining the plumbing fixtures aboard a ship such as lavatories, showers, toilets, sinks, etc.

Sanitary Tank. See Tank, Sanitary.

Sash, Window. A frame for holding the glass. It is generally composed of a horizontal piece at the top, called the top rail, a horizontal piece at the bottom, called the bottom rail or, where beveled in an upper sash, a check rail, the sides called stiles, and pieces dividing the sash into separate lights called mullions or bars.

Saturated Steam. See Steam, Saturated.

Scale. A more or less hard adherent crust which forms on boiler heating surfaces by the depositing of impurities from the feed water. The salts of lime and magnesia are usually responsible for such incrustation.

Scaling Hammer. A hammer used by cleaners to remove the rust scales from iron or steel plates and shapes.

Scantlings. A term applied to the dimensions of the frames, girders, plating, etc., that go into a shipís structure. The various classification societies publish rules from which these dimensions may be obtained and as these rules are the results of continued observation of shipsí structures they give the most reliable information from a practical standpoint that can be obtained. The forces acting on a ship at sea cannot be accurately determined, hence calculations made to determine the size of a member of a shipís structure should be compared with similar calculations on existing practice where possible.

Scarph. A connection made between two pieces by tapering their ends so that they will mortise together in a joint of the same breadth and depth as the pieces connected. It is used on keels, stem and stern frames, etc. Also used to designate the tapering of the corner of a plate where a joint occurs.

ĎScending. The oscillations of a ship in the fore and aft direction. Synonymous with the term "pitching."

Sceptre Recorder. An instrument for recording the water depth under a ship.

Schooner. A sailing vessel with two or more masts rigged fore and aft.

Sconce. A metal bracket, sometimes with a reflector behind it, attached to a beam or bulkhead to hold a candle or lamp.

Scotch Boiler. See Boiler, Scotch.

Scotchman. A piece of wood, hide or metal fitting seized to a shroud or other rigging to prevent chafing by the running gear, etc.

Scout. A war vessel of small size, displacing from three to five thousand tons, carrying a battery of from five to eight guns of moderate size and several torpedo tubes, having large cruising radius and the capabilities of traveling at high speeds.

Scratch Awl or Scriber. A small rod of cast steel with hardened sharp points used for marking lines on the surface of metal.

Screen Bulkhead. See Bulkhead, Screen.

Screen, Clear View. A mechanical means of keeping lookout windows clear and transparent and prevent them from becoming fogged in heavy weather.

Screw. A cylinder surrounded by a spiral ridge or groove, every part of which forms an equal angle with the axis of the cylinder, so that if developed on a plane surface it would be an inclined plane. It is considered as one of the mechanical powers. When used alone the term commonly means a wood screw, having a slotted head and gimlet point, for driving in with a screwdriver. Machine screws are similar, except that they have no gimlet point and have a metal screw thread. They are used for uniting metallic parts. All ordinary forms of bolts have screw threads cut on them, but are not commonly called screws. A special form of wood screw is a lag screw, which is a large size screw with a head like a bolt, so that it may he inserted with a wrench instead of a screwdriver.

Screw Jack. See Jack, Screw.

Screw, Packing. A tool designed for the removal of worn packing.

Screw Propeller. See Propeller.

Screw-Post. See Propeller Post.

Screw-Race. See Aperture.

Screw, Shaft. See Propeller Shaft.

Screws, Rigging. Implements possessing the mechanical advantage of the screw used at the lower ends of shrouds and stays in lieu of dead eyes and lanyards.

Scrive Board. A portable platform made of soft, clears, planed lumber on which a full sized body plan of a ship is drawn, the lines being cut into the surface of the wood in small "U" shaped grooves by means of a scriving knife, to prevent them from being obliterated.

Sculling. The propelling of a boat by means of a single oar over the stern.

Scupper Holes. Drain holes cut through the gunwale of deck stringer angle bar and adjoining shell plate to allow water to drain directly from the gutter or waterway overboard. Where from strength considerations the holes cannot be cut in angle bar plating, the usual scupper pipe is fitted, leading down through decks and the shipís side.

Scupper pipes. The pipes leading from the scupper to the fitting in the shipís side, for carrying accumulations of water from the deck overboard.

Scuppers. Drains from decks to carry off accumulations of rain water or sea water. The scuppers are placed in the gutters or waterways on open decks and in corners of enclosed decks, and connect to pipes leading overboard. The flap valve at the bottom of the scupper pipe is also often called a scupper.

Scuttle. A small opening, usually circular in shape, and generally fitted in decks to provide access as a manhole or for stowing fuel, water and small stores. A cover or lid is fitted so that the scuttle may be closed when not in use. Also applied to the operation of opening a sea valve or otherwise allowing the sea to enter a ship for the purpose of sinking her.

Scuttle Butt. The designation for a container of the daily supply drinking water for the use of the crew. The scuttle butt formerly consisted of a simple wood cask standing on end, having a hole in its upper head or bilge. The more modern one is constructed of metal, well insulated and fitted with a sanitary drinking fountain. On large vessels provided with a refrigerating plant the scuttle butt is usually fitted with cooling coils connected to the refrigerating system.

Sea Anchor. See Anchor, Sea.

Sea Chest. A term applied to a casting fitted to the shell of a vessel for the purpose of supplying water from the sea to the condenser and pumps, and also for discharging water from the ship to the sea..

Sea Cock, Sea Connection. A sea valve secured to the bottom of the vessel for use in flooding the ballast tanks, supplying water to the fire pumps and sanitary pumps and other purposes. While these sea valves are sometimes called sea cocks, the ordinary type of valve is always used.

Sea Injection Pipe. See Pipe, Sea Injection.

Sea Painter. A long line led from a point well forward on a vessel outboard of the rail and awning stanchions to a lifeboat and bent to the inboard side of the forward thwart in such a manner that it may be quickly cast off. Hauling on the painter or when a strain is otherwise brought on it sheers the bow of the lifeboat away from the vessel.

Sea Room. The distance separating a vessel from the nearest point at which she could take the ground or meet other obstruction to navigation.

Sea Valve. See Valve, Sea.

Seam. A term applied to an edge joint whether flush or lapped. Also applied to the slight crevice between the ends or edges of butt joints.

Seam Straps. A term applied to a narrow strip of plate serving as a connecting strap between the butted edge of plating. The strap connections at the ends are called butt straps.

Searchlight. A powerful electric lamp placed at the focus of a mirror, which projects the light in a beam of parallel rays. The apparatus consists essentially of a base and turntable fitted with arms carrying trunnion bearings, in which is mounted the barrel or drum containing the mirror and lamp with its operating mechanism. The drum may be elevated and depressed and turned in azimuth by means of handles at the back, or by either mechanical or electrical distant control gear.

Searchlight, High Intensity. A searchlight of great brilliance distinguished from the ordinary type in being provided with carbons and lamp mechanism of special design, the positive carbon being cored, said core material being comprised of metallic salts which volatilize, becoming highly luminous when subjected to the temperature of an electric arc. The incandescent gas produced is held within the arc crater by the impinging of a flame from the negative carbon.

Seating, Boiler. See Boiler Foundation. .

Secret Blocks. See Blocks, Secret.

Section. A drawing showing the internal arrangement of a ship as it would appear if cut by a plane, usually longitudinally or transversely,

Section, Midship. See Midship Section.

Sectional Area, Curve of. A curve, plotted from a straight base line, representing the length of the ship, the ordinates of which represent to scale the areas of the vesselís immersed cross sections at corresponding points. The area under this curve represents to scale the volume of the displacement. The center of gravity of this area represents the longitudinal center of buoyancy of the displacement.

Sector. Known in France as the compass de proportion, this mathematical measuring instrument has two lombs or arms, and is essentially a brass-jointed ruler, the arms of which are engraved with various sets of graduated lines of scales, or tables, sines, tangents, and the like.

Seize. To secure one rope to another, two or more parts of the same rope together, or a fitting of any kind to a rope or other object by binding with any small stuff.

Seizing. A binding made of seizing stuff securing two ropes or two parts of the same rope together. Seizings are named according to their location and use, as throat or eye seizings, round seizing, flat seizing, etc. Several different ways of passing the seizings and making the finish are in general use for each of the above kinds. Seizings are also used to secure Scotchmen to rigging, cleats, davits, etc.

Seizing Stuff. A tarred hemp, right-handed, three-stranded small stuff of two, three or four threads to the strand. It is heavier and stronger than house-line or roundline, being made by machinery and finished similar to the larger sized ropes. Seizing stuff is also made in galvanized annealed steel wire, six wires around a wire center, varying from l/l6 inch to 1/4 inch diameter.

Self Opening Die Heads. A die head used on automatic screw machines and twists.

Sennit. A braided cordage made from rope yarns, spun yarns, and untarred marline plaited by hand in a number of patterns. Common or flat sennit is a plain plaiting of five or seven strands; French sennit is more open than the flat sennit, but similarly made of a greater number of strands; round sennit and square sennit take their names from their form, both consisting of an even number of strands. The former is plaited around a center or heart, while the latter is without a heart.

Sentinel Valve. See Valve, Alarm.

Separator. A device for removing water from steam. There are many varieties. That based on the centrifugal action developed by whirling or repeatedly changing the direction of steam is typical of such devices when fitted outside the boiler. In certain types of water tube boilers, perforated plates are fitted in the upper drum. The steam on its way to the steam pipe is subjected to a straining action by these plates.

Separator, Steam. A mechanism designed to extract the moisture and impurities from saturated steam. It is fitted on the steam line between the boiler and the engine.

Series Motor. See Motor, Series.

Serve (to serve a rope). To wrap any small stuff tightly around a rope which has been previously wormed and parceled. Very small ropes are not wormed.

Service. The covering of small stuff applied to a rope as a protection against the weather.

Serving Stuff. The various materials used in serving ropes, such as spun yarn, rope yarn, marline, house line, and round line. Where great neatness is not essential spun yarn is generally used, while marline, house line, and round line are used for neater work, being laid up more smoothly and of a superior quality material.

Set. Metal mold or template for use on the bending slab.

Set. Sometimes designated as "permanent set." The permanent deformation resulting from the stressing of an elastic material beyond its elastic limit.

Set Iron. A flat bar of soft iron used in transferring the shape of the frame from the scrive board to the bending slab.

Set Screws. A machine screw with either a slotted or square head used for the purpose of holding a part in place.

Set Up. To tighten the nut on a bolt or stud; to bring the shrouds of a mast to a uniform or proper tension by adjusting the rigging screws or lanyards through the dead eyes.

Settling Tanks. Oil tanks used for separating entrained water from the oil. The oil is allowed to stand for a time or until the water has settled at the bottom, when the latter is drained or pumped off.

Sextant. A hand navigating instrument for measuring, by reflection, the angle subtended at the eye by two distant objects by a single observation. It is the most convenient and accurate instrument yet devised for use where the observer has a very unstable support, as on board ship, and is very generally used by navigators and surveyors for determining the attitude of celestial bodies and the angular distance between them as well as the horizontal angular distance between terrestrial objects. It consists of a rigid frame having a handle, a horizon glass, silvered on its lower half, but clear on its upper half, and a telescope pointing into this mirror, all rigidly attached to the frame. Another mirror, known as the "index glass," is rigidly attached to a movable arm, which carries vernier reading on a graduated limb. A ray of light coming from a distant object strikes the index glass and is reflected to the mirrored part of the horizon glass and thence through the telescope, while a ray coming through the upper half of the horizon glass passes directly into the telescope, each of which set of rays forms a perfect image. The observation consists in bringing the two images into exact coincidence by means of the movable arm when the angle subtended by the two objects is then read off the limb. The name is derived from the fact that the limb of the instrument includes but an arc of 60 degrees of a circle, but owing to double reflection, angles up to 120 degrees may be measured with it. The scale is graduated to 120 degrees in a length of 60 degrees. A different form of instrument, known as the prismatic sextant, measures angles up to 180 degrees.

Shackle. A U-shaped link whose end is closed by a removable pin or bolt, Shackles arc used principally to connect the shots of chain cables, blocks to davit heads and other places where severe stress is brought on the block, rigging to mast bands and deck connections, etc.

Shackle Bolt. A bolt that passes through both eyes of a shackle and completes the link. The bolt may be secured by a pin through each end, or a pin through one end and through the eye, or by having one end and one eye threaded, or one end headed and a pin through the other.

Shackle Bolt Pin. A metal, or rarely, a wood pin, used to secure a chalked bolt. The pin generally has a split end, the two parts being slightly separated to prevent its starting, and is frequently termed a split pin.

Shade Deck. See Deck, Shade.

Shade Deck Stringer. See Stringer, Shade Deck.

Shade Deck Stringer Bar. See Stringer Bar.

Shade-Deck Vessel. A vessel constructed with a continuous upper deck of light scantlings and fitted with openings in the sides between the main and upper decks.

Shaft Angle. The angle which a propeller shaft makes with the line of intersection between the designed water plane and the longitudinal center plane of the ship. In many cases the horizontal shaft angle is ignored and only the angle which the shaft makes with the designed water plane is considered. This may be slightly less than the true shaft angle.

Shaft, Crank. See Crank, Shaft. .

Shaft Horsepower. See Horsepower, Shaft.

Shaft, Propeller or Tail. See Propeller Shaft.

Shaft Stools. A term applied to the seatings to which the plumber blocks or line shaft bearings are attached. In addition to supporting the weight of the shafting they have to resist any side bending tendency due to the vibrations or thrust on the shaft. The overturning force is not nearly so serious as in the thrust block.

Shaft Strut. A term applied to a bracket supporting the after end of the propeller shaft and the propeller in twin or multiple screwed vessels having propeller shafts fitted off from the center line. It usually consists of a boss, fitted with a bushing to form a bearing for the shaft, connected to the side of the ship by two arms of pear-shaped section. The inboard ends of the arms are fitted with palms for attachment to the shell.

Shaft, Thrust. See Thrust Shaft.

Shaft Tunnel. See Tunnel, Shaft.

Shaft Tunnel, Shaft Alley. A watertight passage housing the propeller shafting from the engine room to the bulkhead at which the stern tube commences. It provides access to the shafting and its bearings and also prevents any damage to the same from the cargo in the spaces through which it passes.

Shaft, Weigh. A shaft running parallel to the crank shaft, used for the purpose of controlling the valve gears on a reciprocating engine. It is carried in bearings attached to the upper portion of the columns of the engine, and is fitted with one arm for the bridle rods to each link and one arm for connection to the reversing gear. The arms connected to the link bridle rods are slotted with a block working on a hand screw gear which permits independent adjustment of each link.

Shafting. Cylindrical rod or tubing used, in general, for the transmission of rotary motion from the source of power, the engine, to the propelling device, the propeller, or paddle wheel.

Shakes. Splits or checks in timbers which usually cause a separation of the wood between annular rings.

Shank Painter. A rope or chain passed around the shank and flukes of an anchor confining it to the billboard.

Shaper. A machine for planing small parts in which the work table is stationary, the cutting tool being held by a tool post on a moving ram which travels over the work.

Shaper, Crank. In this type of shaper a crank motion is used to drive the ram.

Shaper, Double Head. A type of shaper designed with two rams or heads. These machines also have two tables and may be used for planing large pieces of work and for work involving planing two surfaces some distance apart.

Shaper, Geared. In this type of shaper a rack and pinion are used to drive the ram with a slow cutting stroke, a quick return being effected by shifting an open and crossed belt arrangement.

Shapes. Bars of rolled mild steel or of extruded non-ferrous metals, having certain forms of cross section throughout their entire length. The forms of cross section given are such as to lend to strength and rigidity in fabrication.

Shear, Angle. A machine specially designed for cutting off angle bars.

Shear, Gate. A machine for cutting and trimming long sheets or plates. These machines are often designed for making cuts of from two to ten feet in length in one operation, the thickness of plate varying from 1-16" to 1 7/8", depending upon the capacity of the machine.

Shear Legs. An apparatus rigged up for raising and moving heavy weights where a crane or derrick is not available.

Shearing. The removing of excess material from the edges of plates or shapes by means of shear .

Shearing Machine. A machine used for splitting or trimming steel plates and for cutting of bars or structural shapes. Shearing machines are made both in hand and power operated types, and in many cases these machines are also adapted for punching operations by replacing the shear blades with one or more punches and dies.

Sheathed, Sheathing. A term applied to the wood planking fitted over a steel deck, to the planking fitted over the underwater portion of a steel shell, and to the copper plating with which the bottom of a wood vessel or a steel vessel sheathed with wood is covered.

Sheave. A wood or metal disc having a groove around its cylindrical surface to allow a rope or chain to run over it without slipping off.

Sheave Holes. A term applied to apertures cut through a mast, boom, or spar in which sheaves are installed.

Sheepshank. A method of quickly but temporarily shortening a rope. It is made by laying two long bights side by side and half hitching each part over the end of the near bight.

Sheer. The longitudinal curve of a vesselís rails, deck, etc., the usual reference being to the shipís side; however, in the case of a deck having a camber, its centerline may also have a sheer. The amount by which the height of the weather deck at the after or forward perpendicular exceeds that at the mid perpendicular. Mean sheer is the average of the sheers forward and aft as just defined.

Sheer. The deformation of a solid body equivalent to a sliding of each of the parallel infinitely thin laminae that may be considered to form it upon that next below it, in the same direction and by the same infinitesimal amount.

Sheer Line. The longitudinal curve of the rail or decks, which shows the variation in height above water or freeboard, throughout the vesselís entire length.

Sheer Mold. A molding placed flush with the top and along the outside edge of a wood deck.

Sheer Off. To steer clear of or keep away from some danger or object.

Sheer Pole, Sheer Batten. A term applied to a steel or iron rod fitted, for and aft, along the lower portion of the shrouds to hold them in place.

Sheerstrake. The strake of shell plating that runs along the level of the main or upper decks. Plates running along the level of lower decks are not called sheerstrakes. Sheerstrakes, on account of their distance from the neutral axis of the ship, are important strength members, and when adjacent to a strength deck they are made thicker than the side plating. The sheerstrake in wood ships is the strake of outside or shell plating that runs along the sides of the main or upper decks.

Sheerstrake Plate. See Plate, Sheerstrake.

Sheet. A rope or chain used to haul the clew of a sail out toward the yard arm or downward toward the deck and aft. Sheets take their names from the sails they extend, as "fore sheet," "main-staysail sheet," "mizzen-topgallant staysail sheet," etc.

Shelf. A wood ship term applied to the fore and aft timber that is fastened to the frames to form a support for the enclosure of the deck beams.

Shelf, Hold Beam, Main, Upper Deck, Etc. A fore and aft timber running under and supporting the ends of the various tiers of beams.

Shell Doublings. A term applied to extra plates fitted over the portions of the shell plating requiring additional strength. Also fitted as compensating plates in the way of ports or apertures.

Shell Landings. A term applied to that portion of the edges of shell plating occupied by the laps.

Shell Liners. See Frame Liners.

Shell Lugs. Short pieces of angle bar fitted to the shell plating between frames for the purpose of attaching stringer plates on the shell plating.

Shell Plating. See Plating, Shell.

Shell-Room. Spaces or compartments devoted to the stowing of projectiles.

Shelter Deck. See Deck, Shelter.

Shelter Deck Sheerstrake. The strake of outside plating adjacent to the shelter deck.

Shelter Deck Stringer. See Stringer, Shelter Deck.

Shelter Deck Stringer Bar. See Bar, Stringer.

Shifting Beam. A term applied to a portable beam fitted in a hatchway for the purpose of supporting the hatch covers. The ends of the beams are fitted in slotted carriers attached to the inside of the hatchway coamings.

Shifting Boards. A portable bulkhead generally constructed of wood planking.

Shifting Valve. See Valves, Shifting.

Shim. A piece of metal or wood placed under the bedplate or base of a machine or fitting for the purpose of truing it up.

Ship. A vessel having three or more masts. In a three-masted ship the masts are fore, main and mizzen, and all are square rigged. In a four masted ship the aftermost mast is called the jigger. It may be either square or fore-and-aft rigged.

Ship Chandler. An individual or firm handling provisions, outfit, or other commodities for a shipís use.

Ship, Longitudinal Framed. A ship constructed of widely spaced, deep or belt frames which support which support a relatively large number of small fore and aft frames.

Ship, Transverse Framed. A ship consisting of a large number of relatively small, closely spaced, athwartship frames, reinforced in the bottom by vertical floor plates and working in conjunction with widely spaced, fore and aft, deep girders, such as the keel, longitudinals, and side stringers. This is the usual type of vessel.

Shipfitter. A mechanic who lays out the shape, location of rivet holes, or openings, and bevels upon hull plates and shapes by means of templates or dimensions from the ship or from data obtained from plans or mold loft, in order that such plates and shapes may be satisfactorily fitted into their proper places in the shipís structure.

Shipshape. A nautical term used to signify that a whole vessel or the portion under discussion is neat in appearance and in good order.

Shipwright. A nearly obsolete term applied in wood shipbuilding where but a small amount of mold loft work was necessary to the men who set the frames, kept the form fair, and performed such work as would not lie within the province of a carpenter.

Shipyard Plate. This is not a utensil, but a bronze or brass plate inscribed with the name of the shipyard where a vessel was built.

Shoes. See Keel, False. .

Sholes. Small pieces of timber or plank placed under the heels of shores, etc.

Shore, Spur. A brace placed with one end resting on the side of a ship to keep it at a desired distance from the side of dock or dry dock.

Shores. Pieces of timber placed in a vertical or inclined position to support some part of a ship, or the ship itself, during construction.

Shores, Bilge. Short heavy timbers used in addition to the bilge blocks as supports for a vessel at or near the turn of the bilge.

Short Splice. A splice made where the rope is not required to render through a block and where an increased diameter is not objectionable as in straps, clings, pendants, etc. Less length of rope is required than when a long splice is made, which is sometimes the paramount consideration. The strands are first unlaid for a short distance, the ends of the ropes brought together, the strands interlaced and tucked through the lay of the other rope.

Shoveling Boards. Boards placed in the bottom of coal bunkers forming a level surface.

Shroud. A principal member of the standing rigging, consisting of hemp or wire ropes which extend from or near a mast head to a vesselís side or to the rim of a top to afford lateral support for the mast.

Shroud-laid Rope. See Rope, Shroud-laid.

Shroud Ring, Turbine. See Turbine Shroud Ring.

Shunt Motor. See Motor, Shunt.

Sick Bay. A name applied to the space on board ship where the members of the crew or passengers are given medical treatment. As generally used, the term covers all rooms or compartments assigned for treatment of the sick, such as the dispensary, operating room, contagious ward, etc.

Side Bar Keel. See Keel, Side Bar.

Side Bunker. A bunker located in a vesselís wings usually in way of the boiler rooms. Bunkers of this type are common on coal burning vessels largely because of the facilities thus afforded for feeding coal into the fire rooms.

Side Frame. See Frame, Side.

Side Girders. See Stringer, Side.

Side Keelson. See Keelson, Side.

Side Lights. See Lights, Side.

Side Plating. A term applied to the plating above the bilge in the main body of a vessel. Also to the sides of deck houses, erections, etc.

Side Scuttle. A term applied to an opening in the side of a ship provided for the discharge of garbage, etc.

Side Stringer. See Stringer, Side.

Siding of a Frame. The fore and aft dimension of a frame.

Siding of a Keel. Its width.

Siding of a Stem. Its athwartship dimension.

Siding of a Sternpost. Its athwartship dimension.

Sill. The foundation timber of a deck house, on which the framing is erected. Also called Coaming.

Sill, Dry Dock. The stone, concrete or timber ledge at the bottom of the entrance of a graving dock against which the gates or caisson abuts when closed.

Sill, Window Frame. The horizontal piece at the bottom.

Single Acting Pump. See Pump, Single Acting.

Single Riveting. See Riveting, Single.

Single Whip. A rope rove through a single fixed block.

Siren, Steam. A form of whistle in which the sound is produced by the action of steam in passing through corresponding openings in two concentric and oppositely revolving discs or cylinders. The pitch and intensity are raised and increased respectively with the speed of rotation. The steam is permitted to escape through a funnel shaped opening or trumpet so as to increase the volume of sound as much as is possible.

Sister Blocks. See Blocks, Sister.

Sister Hooks. Hooks made in halves and set on eyes facing each other in such a manner that they may be made to function as a link

Sister Keelson. See Keelson, Side.

Skeg. The after end of the keel. It forms a support for the sternpost and sometimes projects sufficiently to form a step for the rudder post.

Skeleton Mold. See Mold, Skeleton.

Skeleton of a Vessel. The transverse and longitudinal members comprising the framework of the shell and decks.

Skew Inclination. The inclination resulting from the simultaneous action of both transverse and longitudinal forces.

Skiff. A lightly built pulling boat. The term is sometimes loosely used as applying to pulling boats in general.

Skin. This term is usually applied to the outside planking or plating forming the watertight envelope over the framework. It is also applied to the inner bottom plating where it is called the inner skin.

Skin, Inner. A term applied to the inner bottom plating. This usually extends only across the bottom, but sometimes is carried up the sides.

Skin, Outer. A term applied to the outside plating, shell or planking of a ship.

Skin Resistance. See Resistance, Skin.

Skylight. A built up frame of metal or wood having glass lights fitted in the top and installed over a deck opening for the purpose of furnishing light and, where the top covers are hinged; ventilation to the spaces below.

Skylight Coaming. The vertical sides of a skylight frame whether of steel or wood.

Skylight Cover. The top of a skylight, having glass lights fitted in it and often hinged and operated from below. Brass rods are generally fitted over the glass for protection.

Skylight Gratings. A term applied to the gratings protecting the glass lights in a skylight cover. They are usually constructed of brass rods.

Skylight Lifting Gear. A gear composed of rods, pinions, worms or gears, levers and hand wheel for opening and shutting a skylight cover from below. This gear should be designed to operate easily and to support the cover firmly when open.

Slabs or Blocks, Bending. Square or rectangular iron castings of adequate strength, fitted with numerous regularly spaced holes for the reception of dogs or other holding devices. A number of these units are fitted side by side, their upper surfaces uniting to form a continuous floor of sufficient area. Upon this floor heated shapes such as frame bars are bent to the required contour and then fastened by means of dogs placed in the holes until a permanent set has been assumed.

Slack. The opposite of taught, not fully extended as applied to rope; to slack off means to ease up, or lessen the degree of tautness; as applied to water, that state of the tide when it has ceased running and appears stationary just before it turns, either at high or low water.

Slack Away, To. To pay out a rope or cable by carefully releasing the tension while still retaining control.

Slackness. The contrary of ardency, being that property of a ship by virtue of which she tends to throw her head away from the wind. Ships possessing this characteristic must be held on their course by keeping the helm a-lee. The reason for this tendency is found in the resultant lateral resistance of the vessel being behind or abaft of her resultant wind pressure.

Sleepers. Timbers placed upon the ground or on top of piling for supporting the cribbing, keel and bilge blocks.

Sleeve. A casing, usually of brass, fitted over line or other shafting for protection against wear or corrosion.

Slew. To yaw from side to side while at anchor or being towed.

Sling. A length of chain or rope employed in handling weights with a crane or davit. A cask or barrel sling usually consists of a length of rope having the two ends spliced together; the chains or ropes attached at the bow and stern of a small boat to which is hooked the tackle when it is hoisted or lowered; the chain or rope extending from a mast head to the center of a yard forming a support for same.

Slip. The difference between the pitch of a propeller or the mean circumference of a paddle wheel and the advance of same through the water corresponding to one revolution. An inclined launching berth.

Slipways or Berths. The space in a shipyard where a foundation for launching ways and keel blocks exists and which is occupied by a ship while under construction. The term berth also designates the space a ship occupies at a pier or at an anchorage,

Sloop. A vessel having one mast and fitted with fore- and-aft sails.

Sloop-Rig. A single masted fore and aft rigged vessel. Distinguished from a cutter principally by her broad, shoal hull with its accompanying center board.

Slop Chute. A chute hung over the shipís side or built into the ship with discharge through the shipís side, for discharging garbage overboard.

Slotting Machine. A machine which operates on the same general principles as a shaper, except that the ram which carries the planing tool moves in a vertical direction at right angles to the work table.

Slotting Machine, Crank. In this type of slotting machine, a crank motion is used to drive the ram.

Sluice. An opening in the lower part of a bulkhead fitted with a sliding watertight gate or door having an operating rod extending to the upper or upper decks.

Sluice Cock. Either a cock or valve attached directly to a bulkhead to permit floe of a liquid directly from one compartment to another. A cock differs from a valve in that the liquid flows through a channel bored through the tapered plug forming the cock and in no case is it necessary to turn the handle more than a quarter turn to open it fully.

Sluice Valve. Sec Valve, Sluice.

Sluice Valve Rod, Sluice Valve Spindle. The operating rod by which the sluice valve, usually located at the bottom of a compartment, can be opened or closed from a deck above.

Slush. Grease obtained from the meat boiled in the coppers and used as a lubricant and for slushing the spars after scraping.

Smoke Box. The casing attached to the end of a boiler to which the uptake is connected.

Smoke Box Door. A door attached to the smoke box to provide access for inspecting and cleaning the tubes.

Smoke Sail. A piece of canvas hoisted close to the galley smokepipe to carry the smoke from the deck during a head wind or hoisted at the foremast to prevent soiling the mast.

Smoke Stack. A metal chimney or passage through which the smoke and gases are led from the uptakes to the open air.

Smoke Stack Cover. A canvas cover used to close the top of the smoke stack when the fires are drawn for any length of time such as during a repair period.

Smoke Stack Paint. See Paint.

Snap Switch. An electrical device for opening and closing a circuit by turning an insulated button. A snap switch for marine work is usually arranged so that the electrical connections are protected by a watertight cover.

Snatch Block. See Block, Snatch.

Snubbing. The checking of a vesselís headway by means of an anchor and short cable. The checking of a line or cable from running out by taking a turn about a cleat, bitts, or similar fitting. Also drawing the waterlines or diagonals of a vessel in suddenly at their ends.

Socket, Davit. See Davit Socket.

Soda Cock. See Condenser, Soda Cock.

Sole-Piece of Stern Frame. The lower fore and aft piece of a stern frame connecting the propeller and stern posts.

Sole Plate. A term applied to the top plate of a foundation to which the base of a machine or piece of equipment is bolted.

Solid Frame. Described under frame.

Soot Blower. A cleaning gear designed to clean the fire surfaces of steam boilers and remove the soot. These results are accomplished by means of steam jets.

Sounding. Measuring the depth of water or other liquid.

Sounding Line. The fine piano wire or wire rope used with a sounding machine.

Sounding Machine. A machine which has almost wholly superseded the antiquated and clumsy deep-sea lead, being designed to ascertain, accurately and quickly, the depth of water at rather high speeds, say up to 16 or 17 knots, in depths not exceeding 100 fathoms.

Sounding Pipes. See Tubes, Sounding.

Sounding Rod. A light metal rod, graduated as desired, for lowering into a sounding tube to determine the depth of liquid in a compartment or tank.

Sounding Tube Deck Plate. See Deck Plate, Sounding Tube.

Sounding Tubes. See Tubes, Sounding.

Spacing of Frames. See Frames, Spacing.

Span. A rope whose ends are both made fast some distance apart, the bight having attached to it a topping-lift, tackle, etc. A line connecting two davit heads so that when one davit is turned the other follows.

Spanish Windlass. A makeshift purchase consisting of a rope, a post or roller and a lever. One end of the rope is attached to the object to be moved, a turn is taken around the post and the other end secured to a fixed object. The lever is then inserted in the bight of the rope at the post and by turning it around a considerable strain is produced.

Spanker. Sometimes termed the driver. The fore-and-aft sail carried on the mizzen mast of a three masted vessel.

Spanner. A form of open head wrench for use with special fittings whose character is such as to preclude the use of the ordinary type of wrench.

Spar. A term applied to a pole serving as a mast, boom, gaff, yard, bowsprit, etc. Spars are made of both steel and wood.

Spar Deck. See Deck, Spar.

Spar Deck Sheerstrake. The strake of outside plating adjacent to the spar deck.

Spar Deck Stringer. See Stringer, Spar Deck.

Spar Deck Stringer Bar. See Bare, Stringer.

Spar-Decked Vessel. A merchant vessel constructed with a complete deck above the main deck and having scantlings above the main deck heavier than those of an awning deck vessel but lighter than those in a full three decked vessel.

Spare Bunker. A bunker for reserve coal.

Spectacle Frame. A single casting containing the bearings for and supporting the ends of the propeller shafts in a twin screw vessel. The frame consists of arms of pear-shaped section extending outboard from each side of the center line of the ship to bosses taking the bearings of the propeller shafts. These arms are usually inclined downward from the center line at an angle of about 30 degrees from the horizontal. The shell plating is worked outboard to enclose the shafts and is attached at the after end to the bosses and arms of the spectacle frame. They are used on steam yachts and large merchant vessels in place of shaft struts or brackets.

Speed Length Ratio. The ratio of the speed in knots to the square root of the waterline length in feet. Similar ships at corresponding speeds have the same value for this expression.

Speeds, Corresponding. See Corresponding Speeds.

Spent Condition. The condition of a vessel when all consumable provisions, stores, fuel and fresh water are exhausted.

Sphere. A globe representing the earth or the apparent surface of the heavens.

Spikes. A stout metal pin headed on one end and pointed on the other. Spikes are used for securing heavy timbers together. Spikes are generally made of square bar with diamond, button or nail type of head and of round bar with countersunk head.

Spirketting. A wood ship term applied to the first strake of inside planking or ceiling above a waterway.

Spirketting-Plate. A vertical side stringer plate attached to the inside of the frames at a lower deck or tier of hold beams.

Splice. A method of uniting two ropes by first unlaying, then interweaving and tucking the strands. See Long Splice, Short Splice, etc.

Sponson Beam. The outer fore and aft girder supporting the paddle wheel box and holding the outer bearing of the paddle wheel shaft.

Sponsons. Fore and aft beams supporting the paddle box structure.

Spot Face. The finishing off of the structure around a hole.

Spray hood. A canvas hood which may be designed in several different shapes, used aboard a boat to prevent the spray from coming on deck or into an enclosure.

Spread. The distance measured transversely to a vesselís longitudinal axis.

Spring. The deviation from a straight line or the amount of curvature of a sheer line, deck line, or beam.

Spring Bearing Foundation. A structural steel foundation built up of lightened plates and angles and surmounted by a heavy base plate to which the holding down bolts of the lower bearing piece are attached.

Spring Bearings. Bearings designed to take the weight of the propeller shaft. If bearings and shaft are properly in line and adjusted, the shaft weight is the only load to which the bearings are subjected. Such bearings quite commonly consist of a lower bearing piece of brass, iron or steel, lined with white metal, and a cap for the protection of the bearing surface and the support of lubricating apparatus.

Spring Line. A hawser run out from any part of a vessel to a point on shore, as a dock, to prevent her going ahead or astern. In the first instance, the line extends from well forward to a point on shore abreast the stern; in the latter, the operation is reversed. Spring lines are also used to turn or spring a vessel around a wharf or dock.

Spring Stay. A horizontal stay between two lower mast heads, derrick posts, etc.

Sprit. A small spar designed to raise the peak of a sail having neither boom nor gaff. The upper end of the spar bears against a becket and its lower end is stepped against and near the foot of the mast.

Sprit Sail. A boat sail carried by a sprit. Originally it was spread under the bow sprit of seagoing vessels from the sprit sail yard.

Sprocket Chain. A chain designed to transmit motion from one sprocket to another. This type of transmission is used in connection with certain types of steering gear and in ammunition hoisting gear.

Spun Yarn. A rough two, three or four-yarn, left- handed, small stuff, made from long tow or old rope yarns loosely twisted together. It is extensively used on shipboard for the coarser seizings, service, etc.

Spun Yarn Rope. See Rope, Spun Yarn.

Spur Beam. A beam running diagonally or fairing into the sides of a ship from the end of a sponson beam, Used on paddle wheel boats.

Square. An instrument used similarly to Gunterís Scales for working on a sea chart.

Square Knot. See Knot, Square.

Square Stern. The stern of a ship whose decks terminate aft in rectangular form. Generally the stern contour is a straight line approximately perpendicular to the surface of the water.

Squatting Speed. That speed at which a vessel changes trim by the stern because of the large bow wave.

Squeegee. A wood block or hoe shaped implement fitted with a handle and a narrow rubber blade secured by screws projecting from the lower edge. The implement is used for removing water from the decks, glass and other smooth surfaces. Also a strap with toggles in the end used to confine a studding sail while being set.

Stability. The tendency which a vessel has to return to the upright when inclined away from that position.

Stability, Dynamical. The amount of mechanical work necessary to heel a ship to an angle from the upright position. It is usually expressed in foot-tons.

Stability in Damaged Condition. The stability which remains after the flooding of one or more compartments with consequent loss of displacement and possible change in character or area of water plane.

Stability, Initial. The resistance offered by a ship to inclination from the upright and measured by the metacentric height.

Stability, Range of. The number of degrees through which a vessel lists before her curve of righting arms becomes 0.

Stability, Statical. The effort which a ship makes when held steadily in an inclined position to return to her natural upright position of equilibrium.

Stabilizer, Gyroscopic. A device for utilizing the gyroscopic properties of a rotating wheel to prevent a vessel from rolling. The wave forces tending to cause roll are exactly counterbalanced by the gyroscopic forces. Rotation of the wheel is by electrical motor and the gyroscopic stabilizing forces are controlled in direction and amount by other electric devices. The stabilizer is usually installed in or near the engine room, but it may be located elsewhere on the ship.

Stable Equilibrium. See Equilibrium, Stable.

Stack, Smoke. See Smoke Stack.

Stage. A floor or platform of planks supporting workmen during the construction or while cleaning and painting either the inside or the outside of a vessel.

Stage Builder. A carpenter who erects platforms or stages in and about a ship on which the workmen stand to perform conveniently the necessary operations incidental to the construction of the ship.

Staggered Riveting. See Riveting, Staggered.

Staging. Upright supports fastened together with horizontal and diagonal braces to which common boards are secured to form a platform. Staging is necessary to provide access to the work both in construction and repair.

Stairs. A built-in staircase aboard a ship.

Stanchion Bulwark. A post or stanchion supporting a bulwark. The stanchions or stays are often made of plating having the inboard edge flanged or of channel bar, the stay making a slight angle with the bulwark plating and being clipped to the top of the bulwark and the deck.

Stanchion, Hold. See Pillar, Hold.

Stanchion, Middle Line. See Pillar, Middle Line.

Stanchion, Quarter. See Pillar, Quarter.

Stanchions. Short columns or support for decks, handrails, etc. Stanchions are made of pipe, steel shapes or rods according to the location and purpose they serve.

Stand By. A preparatory command intended to convey to some one the meaning that he is to be ready to execute promptly a command soon to follow. For one ship to remain in the vicinity of another in order to render whatever assistance may be necessary.

Standing Rigging. Rigging that is permanently secured and is not hauled upon such as shrouds, stays, bob-stays, martingales, mast pendants, etc.

Starboard Side. That side of a vessel to the right hand when looking from the stern toward the bow.

Starboard the Helm. See Port the Helm. A term originally applied to the operation of putting the tiller over to right or starboard side causing the rudder and ship to turn to the left or port. Different countries and different branches of the marine have their own rules as to whether this order means to turn the ship to the right or left.

Stateroom. A private room or cabin for the accommodation of passengers or officers.

Station Pointer. A three-armed protractor, for determining a point on a chart, but mainly used in hydrographic surveys.

Staunch. A maritime term signifying that a vessel is strong, sound, seaworthy.

Stay Bolt. A bolt used for bracing flat surfaces in a fire tube boiler.

Stay Rods, Condenser. See Condenser, Stay Rods.

Stays. The ropes, whether hemp or wire, that support the lower masts, topmasts, top-gallant masts, etc., in a fore and aft direction. They extend from the heads of the masts they support to the next lower mast head of the adjacent forward mast except the lower mast stays which extend to the deck. Any rope used as a tension member, as an awning stanchion stay, a canopy frame stay, etc. A bar, pipe, or plate used as a support against racking, bending, etc.

Stays, Boiler. See Boiler Stays.

Steady. The quality by virtue of which a ship experiences little natural tendency to depart from the upright position when subjected to the action of the waves in a sea-way. It results from a moderate metacentric height.

Stealer Plate. See Plate, Stealer.

Steam Engine Generator Set. A combination consisting of a reciprocating engine and an electric generator on the same shaft. Such sets are used for power and lighting in shipyards as well as on board ships.

Steam Gage. See Boiler Gage, Steam.

Steam Hoist. See Hoist, Steam.

Steam Jacket. A chamber surrounding the cylinder barrel of a reciprocating engine. To this chamber fresh steam is admitted for the purpose of keeping the body of the cylinder as nearly as may be at a uniform temperature. Such an arrangement is effective in avoiding the injurious effects of the cooling action of the exhaust steam on the cylinder walls. In modern high class engines the heads or covers are jacketed as well as the barrel.

Steam, Mixed. The intermingling of saturated with superheated steam.

Steam Ports. The passages from the steam chest to the cylinder through which the steam enters and those from the cylinder to the outer air or condenser for the escape of exhaust steam. Such passages are made as short as possible so that the clearance volume is not unduly increased, but they must be of sufficiently great area so that the pressure of incoming steam is not unduly decreased or excessive back pressure developed in outgoing steam.

Steam Reducing Valve. See Valve, Reducing Steam.

Steam, Saturated. Steam containing as much water as it is possible for it to absorb. When steam separates from the water in which it is generated, it is saturated and has the same pressure and temperature as the water. If in addition to the saturation, it contains water in suspension, it is called wet steam.

Steam, Superheated. Dry steam having a higher temperature than saturated steam at the same pressure. Superheated steam is produced by adding heat to saturated steam that has been removed from contact with the water from which it was generated.

Steam Trap. An apparatus used to collect the water of condensation in steam cylinders and piping and to discharge it automatically either to the boiler, feed tank, condenser or hot well, without wasting steam.

Steam Vessel. See Vessel, Steam.

Steel Deck. See Deck, Steel.

Steel and Iron. Steel is primarily an alloy of iron and carbon, the carbon content ranging from a trace to nearly two per cent. It is capable of being cast into ingots or molds of various shapes. Sulphur and phosphorous are generally present as impurities while silicon and manganese are added for definite reasons. Classes Ė Steel may be classified with relation to the common method of manufacture employed such as crucible, open-hearth, Bessemer, Electric, etc. or by the use for which it is suitable such as machinery or tool steel.

Machinery Steel

Machinery Steel is often classified as mild, medium or hard; also applied to alloy steel such as nickel, vanadium, chrome-nickel, and chrome-vanadium and zirconium steel.

Mild Steel

Mild Steel is soft, having a carbon content of not over 0.02 per cent and it will not harden when suddenly cooled by quenching. Purpose: Mild Steel is used in the manufacture of chain; it is rolled into sheets and strips for flanging, cupping and drawing, galvanizing and corrugating; it is rolled into rods for rivets and bolts; it is used for crucible stock.

Medium Steel

Medium Steel is harder and stronger than mild steel and will appreciably harden when suddenly cooled by quenching. Purpose: Medium steel is used in miscellaneous castings and forgings such as engine and machinery forgings, deck plates, floor plates, boiler plates, structural steel shapes, rods for rivets, bolts and nuts, etc. For castings such as stern frames, rudder frames, high pressure steam piping and fittings, engine bed plates, etc.

Hard Steel

Hard steel is steel harder than medium steel and thus less ductile. It fatigues more quickly under repeated stresses. Purpose: Hard steel is used in forgings for machinery and engines; it is rolled into plates and rods and employed in the manufacture of steel castings.

Process Definitions

Crucible Steel is manufactured by the crucible process, which consists of charging crucibles made of high refractory materials, with known ingredients and submitting them to a temperature sufficiently high to melt all of the charge. This temperature is then held until the charge becomes homogeneous, after which the several crucible charges are usually poured into a ladle and from that poured into ingot molds or molds of special patterns, producing steel castings. All grades of machinery steel may be made by the crucible process as well as all grades tool steel.

Open Hearth Steel is produced in a furnace known as an open hearth. The open hearth furnace is a reverberatory, regenerative furnace, and is usually heated by producer or natural gas. The gas and air pass through a series of heated checker work which raises the temperature of the gas and air before they enter the combustion chamber in which the metal is charged. Open Hearth furnaces are of two types, depending upon the lining of the bottom. All grades of machinery steel are made by the Open Hearth Process and also the cheaper grade of tool steel.

Acid Open Hearth Steel is produced in an open hearth furnace, the bottom of which is lined with ganister or silica brick. The sulphur and phosphorus content of the charge is not appreciably changed by the acid open hearth process.

Basic Open Hearth Steel is produced in an open Hearth furnace, the bottom of which is lined with magnesite brick. Generally a layer or two of chrome brick is placed between the magnesite lining and the silica brick sides to prevent chemical action. Both the sulphur and phosphorus content of the charge may be appreciably reduced by this process, the amount of reduction being dependent upon the temperature and the length of time employed for the melt.

Bessemer Steel is produced by the Bessemer process, which consists of a large receptacle usually lined with ganister, the bottom of which is provided with holes through which air is forced. The charge consists of molten pig iron direct from the blast furnace and the effect of the current of air passing through the molten metal is to burn out the carbon until only the required content is remaining. Only certain grades of machinery steel are made by this process.

Tropenas Steel is produced in a furnace similar to the Bessemer except the blast of air enters through the side of the converter and thus passes over the charge instead of through the charge. Tropenas steel is employed extensively in the production of steel castings.

Electric Steel is produced in a modified open hearth furnace; it is not provided with checker work and is heated by means of an electric current. On account of the absence of gases which contain sulphur, which the steel absorbs at high temperature, and on account of the ease with which the temperature may be regulated in the better designs, a superior grade of steel may be produced by this process. All grades of machinery and tool steal are produced by the Electric Furnace Process.


Iron rarely occurs in the free state. It is obtained by the reduction of its ores. Iron usually occurs as oxides called Magnetite, Hematite, Goethite, etc. The iron ore is reduced in the blast furnace and the product obtained is called pig iron.

Cast Iron is usually remelted pig iron and is divided into two classes namely, gray and white.

Grey Cast Iron contains about one per cent of combined carbon, the remainder being graphitic or combined, Grey Cast Iron is used in the manufacture of iron castings of all sizes and descriptions where no further heat treatment is employed, such as motor frames, engine frames, machine tool frames and beds, steam and gas engines, cylinders and valve chests, cylinder liners and piping, etc.

White Cast Iron is exceedingly hard, practically all the carbon content existing in the combined form. It is used where great hardness is desired and where a shock resisting material is not required. White cast iron is often heat treated in such a manner as to change its combined carbon to graphitic carbon. This process is called malleabilizing.

Malleable Iron Castings are produced by submitting white cast iron castings properly packed to a high temperature for a long period of time. Often these castings are packed in a carbon absorbing material such as mill scale, producing white heart malleable castings. Purpose: Malleable iron is employed in the manufacture of pipe fittings and miscellaneous small castings subjected to shock but where great strength is not required.

Wrought Iron is nearly pure iron, containing less than .03 per cent carbon. It is produced by reducing the carbon content of pig iron by burning out, as in puddle iron, or by employing burning charcoal, as in the sinking process, the latter producing charcoal iron. The various processes of manufacture of wrought iron are often referred to as follows: (a) Puddling, (b) bushelling, (c) faggoting, (d) bushelled steel, (e) muck bar, (f) common iron, (g) merchant bar iron, (h) refined bar iron, (i) double refined iron, and (j) bushelled steel bars.

Steep Tub. A wood or galvanized iron receptacle for steeping salted provisions and vegetables in water previous to cooking.

Steerage. The least desirable portions of a vessel as to accommodations for passengers and occupied by those paying the very lowest fare.

Steerage-Way. A term applied when a vessel has sufficient motion to maneuver by the aid of her rudder.

Steering Chain or Ropes. A term applied to the chains or ropes transmitting motion from the steering wheel or engine to the rudder stock.

Steering Column. A pedestal, usually a casting, supporting the steering wheel; and, where shafting is used for steering control, the brass miter gears attached to the steering wheel and leads. An indicator is usually fitted on top of the column to show the angle of the rudder.

Steering Engine. A steam, electric or hydraulic power machine used for turning the rudder and having its valves or operating gear actuated by leads from the pilot house.

Steering Engine, Chain Drum. A term applied to a cylindrical drum on the steering engine having spiral grooves to take the steering chain.

Steering Engine Foundation. A term applied to a seating prepared for a steering engine.

Steering Gear. A term applied to the steering wheels, leads, steering engine and fittings by which the rudder is turned.

Steering Leads. A term applied to the shafting, ropes or chains transmitting motion from the steering wheel to the rudder stock.

Steering Wheel. A term applied to a wheel in which the spokes are continued through the rim for a distance sufficient to provide a good grasp for the hands and which is used for actuating the steering engine or the rudder through its leads. Where there are rope leads a drum is fitted to the hub of the wheel upon which the ends of the steering rope are wound and when the leads consist of shafting, gears transmit the motion from the axis of the wheel. In vessels that are not provided with a steering engine, this wheel usually has a diameter of about five or six feet to provide leverage which is supplemented by gears or purchases in the steering leads. Large wheels, sometimes single, but usually two or more in tandem are also fitted as an auxiliary hand steering gear at or near the steering engine and sometimes on the deck above it

Stem, Stem Post. The bow frame forming the apex of the triangular intersection of the forward sides of a ship. It is rigidly connected at the lower end to the keel. In wood ships the main piece of the bow frame is called the stem.

Stem Cap. A small plate on top of a stempost.

Stem Deadwood. See Deadwood, Stem.

Stem Piece. A filling piece fitted between the stem and knight heads.

Stem Plate. A plate fitted inside the stem on composite ships for strength and fastening purposes.

Stemson. A knee shaped piece joining the forward end of the keelson to the apron.

Stephenson Link. Also Drag Link. A mechanism designed to assist in reversing a reciprocating engine by means of regulating the distribution of the steam in the cylinder. In consists essentially of a curved slotted link of radius equal to the length of the eccentric rods and to the ends of which these attach. In the link slot a carefully fitted block works. To this block, the end of the valve rod attaches. The manipulation of the link position by means of the reversing rod determines the relative influence of the two eccentrics upon the travel and position of the steam valve.

Step, Mast. See Mast, Step.

Steps. See Treads and Treads, Safety.

Steps, Safety. See Safety Steps.

Stern. The after end of a vessel; the farthest distant part from the bow.

Stern Frame. A heavy casting or forging for the purpose of supporting the rudder and the propeller shaft in single screw vessels. It also serves as a frame for rigidly connecting the converging sides of the ship at the stern.

Stern Light. See Light, Stern.

Stern Molding. A term applied to the half rounds, battens or ornamental work fitted around the stern of a vessel.

Stern Pipe. A round or oval casting or frame inserted in the bulwark plating at the stern of a vessel through which mooring hawsers or warps are passed.

Stern Plating. See Plating, Stern.

Stern Port. See Port, Stern.

Stern Post. The main vertical post in a stern frame upon which the rudder is hung.

Stern Post, False or Inner. A piece of reinforcing timber bolted to the stern post.

Stern Post Plate. A plate fitted on the inside of the stern post in composite ships for strength and fastening purposes.

Stern Rope. See Rope, Stern.

Stern Sheets. The seat in the after part of a boat between the thwart and the coxswainís box.

Stern Timbers. See Timbers, Stern.

Stern Tube. The bearing supporting the propeller shaft where it emerges from the ship. It consists of a hollow cast iron or steel cylinder fitted with brass bushings, which in turn are lined with a lignum vitae or white metal bearing surfaces upon which the propeller shaft enclosed in a brass sleeve rotates. In single screw vessels the stern post is bossed out and bored to take the stern tube which projects far enough aft of the post to take a large flat nut. The forward end of the stern tube is connected by a flange to the after peak bulkhead, which in conjunction with a stuffing box fitted around the shaft, makes a watertight joint at this point. Water can enter the stern tube from the after end through grooves in the lignum vitae or white metal bearings and has been found to be a suitable lubricant when it is not mixed with sand or mud. The stern tube in single screw vessels takes the heavy weight of the propeller and must also withstand the side thrust caused when blades are broken off or come out of water. In twin screw vessels there is generally a strut or bracket aft of the tube to support the screw. In twin screw vessels the stern tubes are supported by the side framing and a bulkhead worked at the forward end of the tube. On account of the angle they make with the shell plating the tubes are generally longer than in single screw vessels.

Stern Tube Bearing. A common bearing surface for stern tubes consists of lignum vitae blocks or strips. Water gains access to the stern tube through the grooves in the bearing and on account of the hard oily nature of lignum vitae it forms a satisfactory lubricant. Where the water is sandy or muddy a bearing surface of white metal will be found more satisfactory.

Stern Tube Bushing. A hollow brass cylinder with an outside diameter equal to the inside diameter of the stern tube. There are usually two bushings, one of which is inserted in the after end and the other in the forward end of the stern tube. A flange is cast on one end of the after bushing which shoulders up against the outboard end of the stern tube and is fastened to it by tap bolts. The forward bushing has no flange but is feather keyed to the stern tube to keep it from turning with the shaft. The inboard end of the forward bushing serves as a shoulder for the packing in the stuffing box.

Stern Tube End Plate. A flat ring having its inside diameter about an inch less than the inside diameter of the after bushing. It is tap bolted to the flange of the after bushing and serves the purpose of holding the lignum vitae bearing strips from slipping out.

Stern Tube Gland. A term applied to a short hollow cylindrical casting having a flange on one end and used for compressing the packing in the stuffing box. The compression is obtained by stud bolts inserted in the forward end of the stern tube and passing through holes bored in the flange of the gland. The gland on a stern tube is usually made in halves so that it can be removed easily.

Stern Tube Retaining Strip. A strip of metal of trapezoidal wedge shaped section, riveted or screwed to the inner surface of a stern tube bushing for the purpose of holding the lignum vitae bearing strips from falling out.

Stern Tube Ring Nut. A term applied to a large flat nut that is screwed onto the after end of the stern tube which projects a short distance aft of the stern post. The stern tube is shouldered at the forward end of the post so that when the ring nut is tightened up the tube can not move forward or aft.

Stern Tube Stuffing Box. A term applied to the receptacle for packing around the propeller shaft in the forward end of the stern tube.

Stern Wheel. A paddle wheel located at the vesselís stern and used for her propulsion.

Stern Wheel Steamer. A steam vessel driven by a paddle wheel located at the stern.

Sternson. A knee connecting the after end of the keelson with the stern post. Used in wood ships.

Stiff, Stiffness. The tendency of a vessel to remain in the upright position or a measure of the rapidity with which she returns to this position when inclined by any external force. The degree of stiffness is directly affected by the value of the vesselís metacentric height.

Stiffeners, Bulkhead. See Bulkhead Stiffeners.

Stiles, Window Frame. The vertical sides of the frame.

Stirrups. Short ropes suspended from the jackstay on a yard, having eyes spliced into the lower ends through which the foot rope reeves.

Stock, Rudder. See Rudder Stock.

Stocks. A term to the keel, blocks, bilge blocks, and timbers upon which a vessel is constructed.

Stokehold. That portion of the shipís boiler room from which the fires are fed and cleaned.

Stokehold Ventilator. A ventilator supplying air to the stokehold or fire room. If forced draft is supplied on the closed stokehold system the ventilator supplies air to the forced draft blowers, the quantity of air being that required for combustion in the boilers.

Stoker. An automatic gear for feeding coal to the fires in a boiler. Also a term applied to a fireman.

Stokers. Members of a shipís boiler room force who attend to the fires in the boiler furnaces.

Stool, Pipe. A term applied to small castings or fittings supporting piping. The small castings supporting the deck piping to capstans, winches and windlass are examples.

Stools, Shaft. See Shaft Stools.

Stop Bead. A thin and narrow piece of wood fitted around a door or window frame for the purpose of holding them in place when they are closed.

Stop Valve. See Valve, Stop.

Stop Water. A wood plug driven through a scarph joint to stop water from leaking into the ship. The term is also applied to pieces of canvas soaked in oils, red lead, etc., placed between the faying surfaces of plates and shapes where water or oil is apt to work its way through.

Stopper Chain. See Chain Stopper.

Stops, Rudder. See Rudder Stops.

Store Rooms. Any space or compartment in which are stowed the stores and supplies that are used aboard the ship.

Storm Valve. See Valve, Storm.

Stow. To pack away, to lash in place, or to otherwise secure in position for a sea voyage.

Stowage. The proper distribution and securing of cargo in a vessel so as to avoid damage to either cargo or vessel by the shifting of cargo or by the undesirable conditions of trim and stability resulting from such a shift.

Stowage, Boat. See Boat Stowage.

Strain. The measure of the alteration of form which a solid body undergoes when under the influence of a given stress.

Strainer, Fuel Oil. A strainer located in the pipe line to the oil pump to prevent refuse from reaching and clogging the pump.

Strainer, Macomb. A type of strainer located in a pipe line near a pump to prevent refuse from reaching and clogging the pump.

Strainer, Strum. A strainer fitted on a strum box where box and strainer are separate fittings. The strainer usually consists of a perforated plate or sometimes a bell-shaped casting with projecting lugs to permit flow of water under the edge of the bell.

Strake. A term applied to a continuous row or range of plates. The strakes of shell plating are usually lettered, starting with A at the bottom.

Strake, Bilge. A term applied to a strake of outside plating running in the way of the bilge.

Strake, Bottom. Any strake of plating on the bottom of a ship that lays between the garboard and bilge strakes.

Strake, Doubling. A term applied to a strake made up of two thicknesses of plates. Also to the extra range of plates fitted in conjunction with the regular strake. The sheer strake and topside plate are often doubled amidship for extra strength.

Strake, Drop. A term applied to a strake that is terminated before it reaches the bow or stern. The number of strakes dropped depends on the reduction of girth between the midship section and the ends.

Strake, Garboard. The strake of shell plating adjacent to the keel. This row of plates act in conjunction with the keel and are made heavier than the other bottom plates.

Strake, Inner. A term applied to the inner strake of an in and out system of shell plating. The strakes adjacent to the molded frame line.

Strake, Limber. A term applied to the inside strake nearest the keelson in wood ships.

Strake, Outside. A term applied to the outer strake of an in and out system of shell plating. The strakes which lap on the inner strakes and which are the thickness of the plating outside of the molded frame line.

Strake, Topside. The strake next below the upper or strength deck sheerstrake. The second range of shell plating down from the upper of strength deck.

Strand (of a Rope). An element of a rope; consisting in a fiber rope, of a number of rope yarns twisted together while in a wire rope a primary assemblage of wires.

Strap, Butt. See Butt Straps.

Strap, Seam. See Seam Straps.

Strapped Joint. See Joint, Butt.

Straps, Seam. See Seam Straps.

Straw Boss. A workman who, while working at his trade, directs the work of other tradesmen of the same kind. He usually receives slightly higher pay than the men whose work he directs.

Stream Anchor. See Anchor, Stream.

Stream Forms. Regular shapes conforming to the lines of flow of a liquid.

Stream Lines. The paths followed by particles of water as they pass over the immersed surface of a body moving through the water.

Strength Girder. See Girder, Strength.

Strength Member. Any plate or scantling which contributes to the strength of the vessel. Some members may be strength members when considering longitudinal strength but not when considering transverse or vice-versa.

Stress. The intensity of the force which tends to alter the form of a solid body; also to equal and opposite resistance offered by the body to the change of form.

Stresses, Longitudinal. See Longitudinal Stresses.

Stresses, Pounding. Stresses included in a vessel as she rides among waves by the beating of the water against her bottom. Pounding stresses are of special moment in flat bottom vessels of shallow draft.

Stringer. A term applied to a fore and aft girder running along the side of a ship and also to the outboard strake of plating on any deck. There are three sets of fore and aft girders in the framing of a ship, viz.: Longitudinals or keelsons, which are the approximately vertical strength members in the bottom; Stringers, which are the approximately horizontal strength members on the sides; and Girders, which are the approximately vertical members under the decks. The word stringer is sometimes used to apply to all three groups but it should only be used for the side girders. Also applied to the side pieces of a ladder or stair case into which the treads and risers are fastened.

Stringer Angle Bar. A term applied to the angle bar connecting a deck stringer plate to the outside plating or bulwark. They are usually made up of short lengths running between frames. A continuous angle bar connecting the inner flange of the frames to the stringer plate is sometimes called a stringer bar.

Stringer, Awning Deck. A term applied to the outboard strake of plating on the awning deck.

Stringer, Bar. A continuous fore and aft strength member made up of angle bars or shapes attached to the inside flanges of the frames. Also applied to the angle bar connecting a stringer plate to the shell or frames in which case the name of the stringer is usually placed before it, as Main Deck Stringer Bar.

Stringer, Bilge. A term applied to the fore and aft girder running along the turn of the bilge.

Stringer, Boat Deck. A term applied to the outboard strake of the plating on the boat deck.

Stringer, Bridge Deck. A term applied to the outboard strake of plating on the bridge deck.

Stringer, Bulkhead. See Bulkhead Stringer.

Stringer, Deck. A term applied to the outboard strake of plating on any deck.

Stringer, Forecastle Deck. A term applied to the outboard strake of plating on the forecastle deck.

Stringer, Gunwale. A term applied to the stringer worked along the sides of a weather deck.

Stringer, Hold. Any stringer, plate or bar, fitted along the sides of a ship between the tank top and the lower decks.

Stringer, Hold Beam. A fore and aft plate attached to the top flanges of hold beams at the sides of a vessel and to the shell and frames.

Stringer, Intercostal. A stringer made up of plates cut to fit between frames. Each plate is attached to the frames and shell plating by short angle or bar clips. The plates are usually made deep enough to allow a continuous bar to be attached to the inner edge and to the inner edge of the frames.

Stringer, Lower Deck. A term applied to the outboard strake of plating on the lower deck.

Stringer, Main Deck. A term applied to the outboard strake or strakes of plating on the main deck.

Stringer, Orlop. A term applied to a stringer fitted about half way between the tank top and lower deck in vessels having deep holds. The plates are wider than those composing ordinary stringers and are supported by brackets attached to the frames.

Stringer, Orlop Beam. A fore and aft plate attached to the top flanges of the orlop beams at the sides of a ship and to the shell and frames. Applicable to a deep hold vessel with beams fitted between the lower deck and tank top.

Stringer, Orlop Deck. A term applied to the outboard strake of plating on the orlop deck.

Stringer, Panting. A fore and aft plate, angle, or built up girder fitted in between the side stringers in the bow and stern. Its purpose is to reduce the in and out vibrations or panting of the frames and plating.

Stringer Plates. A term applied to the outboard plates on any deck or to the plates attached to the top flanges of any tier of beams at the sides of a vessel.

Stringer, Poop Deck. A term applied to the outboard strake of plating on the poop deck.

Stringer, Promenade Deck. A term applied to the outboard strake of plating on the Promenade Deck.

Stringer, Quarter Deck. A term applied to the outboard strake of plating on the quarter deck.

Stringer, Shade Deck. A term applied to the outboard strake of plating on the shade deck.

Stringer, Shelter Deck. A term applied to the outboard strake of plating on the shelter deck.

Stringer, Side. A term applied to a fore and aft girder supporting the side plating and located between the bilge and lower deck. The stringer may be intercostal and attached directly to the shell plating, or it may be continuous and attached to the inner flanges of the frames.

Stringer, Spar Deck. A term applied to the outboard strake or strakes of plating on the spar deck.

Stringer, Trunk Deck. A term applied to the outboard strake or strakes of plating on the trunk deck.

Stringer, Turret Deck. A term applied to the outboard strake or strakes of plating on the turret deck.

Stringer, Upper Deck. A term applied to the outboard strake or strakes of deck plating on the upper deck.

Stroke. The distance traveled by the piston in moving from its extreme position at one end to its extreme position at the other.

Structural Bulkhead. See Bulkhead, Structural.

Strum. See Pump Strainer.

Strum Box. The enlarged terminal on the suction end of a pipe and forming a strainer which prevents the entrance of material liable to choke the pipe. Also called Rose box.

Strut, Shaft. See Shaft Strut.

Stud Link Chain. See Chain, Stud Link.

Studding. The vertical timbers of framing of a deck house, fitted between the sill and the plate.

Stuffing Box. A fitting designed to permit the free passage or revolution of a rod or pipe while controlling or preventing the passage of steam, water, etc.

Stuffing Box, Bulkhead. A fitting attached to a bulkhead where it is desired to pass a rod, pipe or shaft through without destroying the steam, air, or watertightness of the bulkhead. A hole of the proper size is bored through the fitting and a receptacle for packing concentric with it is bored part way through. The packing is held in place by a gland.

Stuffing Box, Deck. A fitting similar to a bulkhead stuffing box and attached to a deck where it is desired to pass a rod, pipe or shaft through without destroying the steam, air or watertightness of the deck.

Stuffing Box Recess. See Tunnel Recess.

Stuffing Box, Rudder Stock. A stuffing box fitted where the rudder stock pierces a flat or deck. According to where it is located, its purpose may be either to prevent the sea from coming up into the vessel or water on deck from coming down.

Stuffing Box, Stern Tube. See Stern Tube Stuffing Box.

Submarine. Beneath the surface of the sea. A vessel capable of service below as well as on the surface of the water.

Suction Head. The distance the pump has to lift the fluid to the suction cylinder plus the frictional resistance. For high lifts and relatively small quantities the reciprocating pump is desirable, while for low heads and large quantities of fluid the centrifugal pump is better. Hand pump suctions may be dispensed with if there are separate boiler rooms, or if there is a donkey boiler installed above the upper deck and there are also pumps in separate compartments with connections to both main and donkey boilers. On a large ship hand pumps are not of much use.

Suction Pipe. See Pipe, Suction.

Suction, Pump. See Pump, Suction.

Suctions, Ballast Tank. Pipes and valves connecting the ballast tanks with the pumps for emptying the ballast tanks of water.

Summer Load Line. The waterline to which a vessel is allowed to load when going to sea in the summer time.

Sun Dial. This was a device to show the time, according to the sun, by the shadow cast on graduations from a center pointer.

Sunk Forecastle. A forecastle, the deck of which is raised only a partial deck height above the level of the upper or weather deck.

Sunk Poop. A poop, the deck of which is raised only a partial deck height above the level of the upper or weather deck.

Superheated Steam. See Steam, Superheated.

Superheater. A device fitted to steam boilers and intended to extract from the gasses of combustion heat which would otherwise escape. For cylindrical boilers of the Scotch and similar types the superheater is generally formed of a drum built into the uptake. The hot boiler gases pass through tubes in this drum and the steam from the boiler is brought into contact with these heated tubes. In water tube boilers the superheater consists of additional steam coils located within the boiler casing in the path of the gases through the tube nests.

Superstructure. A structure built above the uppermost complete deck, a pilot house, bridge, galley house, etc.

Surface Condenser. See Condenser, Surface.

Surfacer. A type of wood planing machine.

Swab. A mop made of cotton rope or twine secured to a handle and used for cleaning decks; an opprobrious term applied to a worthless or useless person on board ship.

Swallow. The space or opening through which a rope passes between the rim of the sheave and the frame of the block. A term applied to an oval or round opening in a chock or mooring ring. What a Rivet Counter enjoys doing with a pint of Guinness.

Swamp. To become covered or filled with water.

Swash Plate. A term applied to a vertical plate fitted either athwartship or fore and aft in a tank for the purpose of retarding the flow of the liquid therein. Swash plates are especially necessary in fuel oil tanks and water tanks that are apt to be only partially full as the unrestricted flow of the liquid against the sides of the tanks would be severe.

Sweet Line. A term applied to a curved line when it is smooth and without humps or abrupt breaks. A fair line.

Swifter. The forward shroud on either side of a mast, a length of rope used to keep the capstan bars in their places or passed from bar to bar around the ends in order to distribute the stresses.

Swinging Ship. An operation for determining the local magnetic deviation of the shipís compass and making the proper adjustment. The shipís head is successively brought to each point of the compass and the bearing of a well defined distant object observed.

Switch, Air-Break. An electric switch, the contacts of which make and break contact in the air as contrasted with an oil break switch in which the contacts make and break under oil.

Switch, Knife. A device with one or more hinged copper blades equipped with a handle and so arranged as to open or close an electric circuit.

Switch, Lightning. A switch used to disconnect Radio equipment from the antenna to protect the equipment from being damaged by lightning.

Switch Oil. An electric switch, the contacts of which are submerged in oil. Such switches are commonly used on high voltage alternating current circuits.

Switch, Watertight Snap. See Snap Switch.

Switchboard, Power. One or more panels made of some insulating material such as slate or marble, equipped with apparatus for controlling electrical machinery or circuits.

Swivel. A special link constructed in two parts which revolve on each other. It is used to prevent fouling due to turns in chains, etc.

Swivel Block. See Block Swivel.

Symbols. Conventional characters or marks indicating certain operations to be performed or observed.

Synchronous Converter. An electrical rotary machine having one armature and with the windings so arranged that it operates on alternating current and delivers direct current, or vice-versa. Sometimes called a rotary converter.

Synchronous Motor. See Motor, Synchronous.


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